1. Field of the Invention
The present invention relates to a vehicle headlight. More specifically, the present invention involves reducing the size in the right-left direction of an actuator that rotates a lamp unit in a predetermined direction, by moving a part of the actuator through a guide shaft.
2. Background Art
Examples of vehicle headlights include lamp units having a light source and a reflector that reflects light emitted from the light source disposed in alighting casing constituted by a cover and a lamp housing.
Such vehicle headlights include a type in which the lamp unit is supported by a support portion such as a frame or a bracket so as to be rotatable (tiltable) and the lamp unit is rotated by the driving force of an actuator (see, for example, Patent Reference 1).
Patent Reference 1: JP-A-2008-094275
By the lamp unit being rotated (tilted) in the vertical direction by the actuator, a so-called leveling adjustment is performed to adjust for the optical axis shift that varies depending on the weight of the load on the vehicle. Also, by the lamp unit being rotated in the right-left direction by the actuator, a so-called swivel operation is performed to change the direction of the optical axis so as to follow the running direction of the vehicle.
In the above-described vehicle headlight that performs the leveling adjustment by the actuator, the actuator is disposed below the lamp unit, the lower end of the lamp unit is coupled to a connecting shaft provided on the actuator, and a supporting point (spherical portion) serving as the supporting point of rotation for the leveling adjustment is provided at the upper end of the lamp unit. In the leveling adjustment, by the lower end being moved in the front-rear direction by the driving force of the actuator, the lamp unit is rotated in the vertical direction about the supporting point.
In the vehicle headlight described in Patent Reference 1, the actuator includes a main unit having a driving mechanism and a support portion that supports the main unit so as to be movable in the front-rear direction. The connecting shaft is provided as a part of the driving mechanism. In the main unit, a slide rail that protrudes sideward (outward) is provided on each of the right and left side surfaces. In the support portion, a side wall, which supports the slide rail so as to be slidable, is provided on each of the right and left sides. The side walls are situated on a side (outer side) of the respective slide rails to support the slide rails.
In the leveling adjustment, the main unit is moved in the front-rear direction with respect to the sliding portion by the slide rails being guided by the side walls of the support portion, and the lamp unit is rotated in the vertical direction with the movement of the main unit in the front-rear direction.
However, in the vehicle headlight described in Patent Reference 1, as described above, the slide rails provided on the main unit of the actuator protrude sideward (outward), and the side walls provided on the support portion are situated on a side (outside) of the slide rails to support the slide rails.
Consequently, the width in the right-left direction of the actuator is large. That is, because the slide rails and the side walls protrude sideward (outward), the size of the actuator is increased in the right-left direction.